1. Field of Invention
This invention relates to stair construction and is particularly directed to pre-formed stair construction for facilitating installation of stairways in buildings and the like.
2. Prior Art
In the construction of buildings, the installation of stairways is a labor intensive and time consuming operation which adds substantially to the ultimate cost of the building. A conventional thirteen step stair, as found in most houses, requires two full man days to erect using conventional carpentry methods. To reduce the time and cost involved in installing stairways, prefabricated stairways have been proposed. However, many of the prior art prefabricated stairways are unsightly and many are unsafe, while others are so expensive to produce and install that the ultimate cost is equal to or greater than the cost of stairways constructed by carpenters. Thus, none of the prefabricated stairways of the prior art have been entirely satisfactory.
A search in the United States Patent Office has revealed the following references:
______________________________________ U.S. PAT. NO. INVENTOR ISSUED ______________________________________ 3,474,882 H. Ernst Oct. 28, 1960 4,583,334 R. M. Hubbard Apr. 22, 1986 4,583,335 F. Morellini Apr. 22, 1986 4,706,425 J. J. Brumbalough Nov. 17, 1987 ______________________________________
The prefabricated stairways of Morellini and Brumbalough are complex and would be extremely expensive to produce and install, while the stairways of Erst and Hubbard are unsightly and do little to relieve the labor required for installation.